1. Field of the Invention
This application relates to detergent compositions containing as detergent builders novel compounds which are water-soluble salts of partial esters of maleic anhydride and a polyhydric alcohol.
2. Description of the Prior Art
Today the major components of detergent compositions generally comprise detergent-active compounds and detergency builders. The use of builders is generally considered necessary to improve detergency levels of such compositions. Although, it is not known with any degree of certainty how the builders function in the detergent systems, it is believed that they affect in varying degrees such factors as stabilization and/or anti-redeposition of soil suspensions, emulsification of soil particles, surface activity of the aqueous detergent solutions, solubilization of water in soluble materials, foam or suds producing characteristics of the washing solutions, peptization or deflocculation of soil agglomerates, neutralization and/or buffering of acid or basic soils, sequestering of metallic ions, etc.
In the prior art the most frequently used detergent builders were condensed phosphates, particularly sodium tripolyphosphate, sodium nitrilotriacetate and sodium copolyethylene-maleate. These and similar phosphorus and nitrogen containing compounds also used as builders are thought by many environmentalists to be a major cause of the eutrophication of various natural bodies of water. In other words, it is generally believed that presently acceptable nitrogen and/or phosphorus containing detergent builders significantly contribute to water pollution by providing eutrophication conditions therein which are favorable to the growth of algae and other undesirable aquatic plants and bacteria; rendering said water unfit for human use or desirable aquatic life. Thus there is a need and a desire to reduce or replace existing phosphate and/or nitrogen detergent builders in detergent compositions.
A suitable detergent builder should therefore be biodegradable, should contain minimal amounts of or no elements which cannot be converted into carbon dioxide and water, should be compatible with presently existing detergent materials and additives thereto, such as bleaching agents and the like and should not adversely affect the material to be washed or cleaned.
The detergent builders of this invention permit the aforementioned desirable reduction or replacement of phosphate and/or nitrogen containing builders in detergent compositions and also provide a biodegradable builder for such compositions.